Conventional liquid cleaning means for enabling a motorist to clean the windshield panel of his automobile while in motion on the road, includes a nozzle mount anchored to the vehicle chassis proximate the lower edge of the windshield pane. The liquid is sprayed in an upward and rearward direction. The wiper assembly then wipes the windshield surface having been sprayed with the cleaning fluid.
It is recognized in the art that the orientation of the fluid nozzle is critical to the efficiency of the wiper assembly-based, windshield cleaning system. A slight factory-made maladjustment can make a big difference. Moreover, a suitable nozzle orientation may be effective for a given, limited range of speed only. Other drawbacks concern the relative position of the nozzle mount, being in a corner at the rear edge section of the automobile hood and at the bottom edge section of the windshield pane, and which will therefore be prone to become clogged by external contaminants. This is especially the case in winter in Canada, where snowfalls will produce snow/ice which may melt during daylight and then freeze during night-time. The windshield antifreeze nozzle mount being a downwardly extending cavity in this area, water may engage therein and can eventually freeze at and thus seal the outlet area.
What is more, the conventional rubber blade of the wiper assembly can also become encrusted with a mixture of ice and snow, thus considerably decreasing its efficiency on the windshield glass pane. Various patents have been directed to the heating of the wiper rubber blade: see for instance canadian patents 284,159; 294,619, and 962,813; as well as U.S. Pat. Nos. 3,408,678 and 4,152,808. A major drawback of these patents is that they are limited to heating the bead of the wiper rubber blade, i.e. the anchoring means for anchoring the wiping blade to the wiper frame: this is clearly apparent for example from FIG. 3 of the last-mentioned patent. Hence, the efficiency thereof is reduced, because the blade per se, which engages the windshield surface to be wiped, is not as such directly heated (although it could eventually be warmed by conduction).